1. Field of the Invention
This invention relates to water flow measuring devices and is more particularly directed to an apparatus for measuring the total forces generated by surface and sub-surface currents and other water movements.
2. Description of the Prior Art
At the present time, there is no single apparatus or device capable of determining or measuring with a significant degree of accuracy, the total forces generated by waves and currents of a water column, either continuously or at any specific time. This information is invaluable to scientists and engineers concerned with ocean dynamics having to do with the forces constantly and consistantly being generated by waves, surface and sub-surface currents.
There are two distinct groups or types of apparatus for measuring current fields, from which forces and kinetic energy of a water column can be deduced. The first group includes the taut and compliant instrumented lines in which there are a number of spaced instruments that either record current velocity and direction in the case of the taut wire array or line shape resulting from the forces of the current acting on the compliant line. These systems are highly inaccurate for measuring total instrument forces of the water column for the reason that the instruments are spaced some distance from each other along the full length of the line, leaving unmeasured currents passing the lines between the spaced instruments.
The second method is the free drop or vertically cycling devices in which a water flow measuring instrument moves vertically and measures the entire water column over the period of time that it takes for the instrument to travel the length of the line so that the measure of total forces is not known for any specific moment or time, thereby being at least to that extent, inaccurate in the determination of total forces being generated by the column of water.
My U.S. Pat. No. 3,372,585, belongs to the compliant line group, having a number of slope and azimuth indicators mounted on the line. The accuracy of this apparatus can be no greater than the number of data points derived from instruments attached along the length of the line; the greater the number of instruments mounted on the line, the greater the accuracy; but in any event, this apparatus or any other conventional apparatus is not as accurate as the present invention, as well as being most cumbersome in execution and extremely costly.